WASHINGTON -- General Motors announced four more recalls today covering more than 500,000 cars sold in the United States -- including every Camaro sold since the current iteration of the iconic muscle car went on sale.

The Camaro recall was prompted by an ignition switch problem similar to the one that bedeviled models such as the Chevrolet Cobalt and Saturn Ion, but GM said the switch meets all engineering specifications and is unrelated to the ignition system used in the cars included in the previous recall of 2.6 million vehicles.

The Camaro recall affects 464,712 vehicles sold in the United States from the 2010-14 model years, and another 46,816 sold in foreign markets such as Canada and Mexico.

GM said that a driver’s knee can bump the key fob and knock the ignition switch out of the “run” position, cutting power to the engine. The company said it knows of three crashes, resulting in four minor injuries, that may have been caused by this condition.

Spokesman Alan Adler said the air bags did not deploy in those crashes, but he didn't know the details about the crashes or when they occurred. Adler said GM was advising Camaro owners to "drive the car and be aware of this" problem.

GM said it discovered the key’s potential to be knocked out of position during internal testing this year after the Cobalt controversy began.

The automaker will make the key and fob independent from each other. The current design conceals the key within the fob; the key is released from the fob with the press of a button.

“Discovering and acting on this issue quickly is an example of the new norm for product safety at GM,” Jeff Boyer, the company’s newly appointed vice president of global safety, said in a statement.

The latest round of recalls brings GM’s total for the year to 38 actions affecting 16.5 million vehicles, including 14.4 million vehicles sold in the United States.

GM said it will change the Camaro key to a standard design. The existing Camaro key (pictured) is concealed in the FOB and is opened by pushing a button.

The other U.S. recalls:

 21,567 units of the 2012Chevrolet Sonic subcompact. Attributed to what GM described as a mistake by a supplier, the transmission turbine shaft can fracture in cars with the six-speed automatic transmission and the 1.8-liter four-cylinder engine.

 14,765 units of the 2014 Buick LaCrosse sedan. GM said a wiring splice in the driver’s door can corrode and break, cutting power to the windows, sunroof and door chime under certain circumstances.

 28,789 units of the 2004-11 Saab 9-3 convertible. GM said a cable in the driver’s seatbelt tensioning system can break.

Reaction to Camaro

While the Camaros represent vehicles made after the 2009 GM restructuring, the ignition-key design dates back further, said Jake Fisher, director of automotive testing at Consumer Reports. Parts designed by pre-bankrupt GM are still in wide use, a pitfall for a company trying to get a handle on a record number of recalls this year that has surpassed 16 million vehicles.

“If there is something alarming here, it’s that there are plenty of old GM designs running around the brand new cars at the dealership,” Fisher said in an interview.

The U.S. National Highway Traffic Safety Administration, which is responsible for overseeing safety defects and recalls, had not posted an official Camaro recall notice as of mid-morning, but the agency has received and posted several complaints from consumers.

A complaint dated May 6 on the 2014 Camaro noted "knee bumped key, engine turned off at 60 mph." There were no injuries or deaths reported in that incident.

NHTSA has been criticized by lawmakers for not acting more swiftly to recall GM small cars with defective switches. The agency has awarded five-star safety ratings -- the highest level -- to the 2012-2014 Camaro in front, side and rollover crashes.

Adler said GM would send letters to Camaro owners soon, advising them to visit dealers to get a new key made.

Sales impact?

The new recalls aren’t likely to have a big market impact on GM, which has weathered months of bad publicity over the Cobalt ignition-switch recall while posting strong sales, said Jack Nerad, executive market analyst at Kelley Blue Book in Irvine, Calif.

“It’s remarkable how disconnected the buying public is from this story,” Nerad said. “It doesn’t seem to have affected sales at all.”

GM in May had its best month of U.S. auto sales since August 2008, rising 13 percent to 284,694 vehicles. In April, it reported first-quarter net income, despite $1.3 billion in recall-related costs. Those gains suggest consumers are separating new models on the lot from the older small cars that are part of the ignition-switch recall.

Reuters and Bloomberg contributed to this report.

Editor's note: An earlier version of this story contained a typo that misstated the number of Saab units involved in the recall. The correct figure is 28,789.